140,000 California Homes Just Set a Battery Record During the Heat Wave
Your Home Could Join Them
On September 9, 2026, as a heat wave pushed California's grid to its limits, more than 140,000 home batteries did something no residential fleet had done before. Together, they discharged more than 580 megawatts to the grid, the largest residential virtual power plant dispatch on record, according to Tesla and Sunrun.

Inside the record
Tesla Powerwalls supplied about 517 megawatts from roughly 110,000 units, with about 55 percent of those operated by Sunrun. Batteries from other manufacturers contributed another 63 megawatts, including more than 30,000 non-Tesla batteries dispatched by Sunrun. The California Energy Commission activated its Demand Side Grid Support program when wholesale electricity prices topped $200 per megawatt-hour. The following evening, Southern California Edison requested a three-hour dispatch that yielded more than 140 megawatts. The milestone built on a July 2025 statewide test, when more than 100,000 batteries sustained 539 megawatts of output for two hours. Analysis of that test projected up to $206 million in potential annual savings by displacing gas peaker plants.

A growing movement
Home batteries are no longer a niche product. They are becoming a core part of how California keeps the lights on. The state has also signed SB 913, which directs regulators to create a method for valuing customer batteries that export power during high demand, and SB 905, which pushes utilities toward programs that reward flexible energy use.
Homeowners who participate in these programs are compensated for the energy they provide, while also getting the everyday benefits of a battery.

What a battery does for you every day
For homeowners on SCE, SDG&E, and PG&E, a battery paired with rooftop solar stores daytime energy for the evening hours, when time-of-use rates are highest. It keeps essential loads like the refrigerator, lights, Wi-Fi, and medical devices running during outages. And it positions your home to take part in grid support programs as they continue to expand, subject to program eligibility and rules.

How to join them
Many people assume a home battery requires a large purchase. Through third-party ownership programs, qualifying homeowners can get solar and battery storage installed without buying or financing equipment, while enjoying lower energy costs and backup power. Sunrun, which operated many of the batteries in this record dispatch, is itself one of the country's largest third-party solar providers. More than 140,000 California homes helped carry the grid through a heat wave. If you want your home to be part of the next record, see whether it qualifies.
To find out if your home qualifies for a TPO solar and battery program, visit myhomesolution.org/california_public_utility_commissions